DE10031041A1 - Application data access provision method for computer aided design, involves forwarding request referring to several data objects for further processing, when request is concerned with one other data object - Google Patents

Abstract

A request related to one of application data item is received, referring to several data objects. The request with respect to data object is fulfilled. When the request concerns one other data object of several objects, the request is forwarded for further processing. Independent claims are also included for the following: (a) Computer program product; (b) Application data access providing apparatus

Description

The invention relates to the field of application programs, and in particular the area of providing access to data that is owned by a user application program are processed. The invention can be used for all types of Application programs are used, especially for programs that Process complex data that are internally linked in a plurality of linked data objects are stored. Such programs can be graphical Editing and design programs, document and word processing pro programs, planning and scheduling programs) and so on. In particular, the use of the invention for Programs for computer aided design (CAD programs; CAD = computer aided design), such as those under the brand "AutoCAD" products available from Autodesk, Inc., San Rafael, United States States of America.

The complex data structures of such application programs typically contain typically a large number of different data elements used to achieve the main functionality of the application program. So For example, in CAD programs, each model contains data that reflect the geometry of the parts determine, material specifications, attributes of the parts, global data and so on. All of these data elements are based on the CAD program processed in a predetermined manner to produce graphics model, including different types of parts lists, parts lists (Bill of material = bill of material = BOM) and so on. This processing however, is not very flexible because it is carried out by the program itself or through additional modules, which are manufactured by suppliers, the detailed knowledge need about internals of the program.

It would be desirable to have a more flexible way of accessing that Application program processed internal data and how to use it  Provide data. In particular, it should be for the end user or for independent dependent developers may be able to access the data even if only a limited body of knowledge about the program's internal data structures is available. However, this is not easy to do because the data is typi stored in a complex way. The individual dates elements can be in different data objects across the model be distributed, and the data objects can be in a complicated network structure be linked. Even if some kind of a data hierarchy is taken into account (e.g. assembly level, component level, feature level), it is still difficult to find the appropriate hierarchy level for each data item determine.

Current word processing programs such as those under the Microsoft Word brand offer the ability to sell on a given Set of internal data elements (such as the title of a document or the current page number) under predefined names. This before is limited to comparatively simple data structures, as they occur in the clearly defined field of word processing.

The object of the present invention is therefore to solve the problems mentioned above to avoid me at least partially and a way to access users to provide data elements that are very flexible and that are particularly useful for complex application data structures that have a large number of interlinked Contain data objects that can be used. The invention is preferably intended also enable data access without in-depth knowledge of internal Require aspects of the application program. Another preferred goal Embodiments of the invention is that data access is user friendly is intended to be used by typical end users of the application program can be used.

To accomplish at least some of the above-mentioned tasks, the Erfin a method of providing access to applications data elements of an application program, a computer program product  and an apparatus having the features of the independent claims. The dependent claims define preferred embodiments of the invention.

The invention is based on the idea of using requests that lead to affect at least one application data element without requiring that this Application data element is stored in a data object to which the Requirement relates. The requirement is as broad as possible with regard to processes the data object to which the request refers. Further the request for further processing to at least one other data object forwarded when the request is such another data object concerns.

The invention offers the considerable advantage that the requirement for a data object that does not itself contain the requested data. If necessary, the structure of linked objects at Bear complete or partial completion of the request. With other wor Requests can be made that any data object or even affect all data objects, and such requests are processed, even if the request only refers to a single data object becomes. This enables application data elements that are in complex data structures are included to access even if only a few Information about the entire data structure is known.

The claims contain the wording that the initial requirement is different to a data object from the plurality of data objects created by the user program are processed, "relates". This wording concludes the It occurs that the request contains a reference to this data object the request is directed to this data object and that the request to an object is directed, which in turn has knowledge of the data object (esp In particular, such an object can be a data provider or an extension object of the data object), but the wording is not limited to these cases. The request does not have to refer to a single data object;  in preferred embodiments of the invention it is also possible that the Request relates to multiple data objects.

The step of "fulfilling" the request with respect to the one data object can do any processing or modification of this data object or any Access to this data object included, or it may just be the step to be agree that the data object is not in the overall processing of the request is required so that the request is passed on directly to other data objects can be directed.

In general, the order of the steps mentioned in the claims should not be considered a limitation on the scope of the present invention can be understood. The invention includes all embodiments in which the aforementioned method steps in a different order or in a parallel or in one another toothed (quasi-parallel) manner.

Preferably, a request is made from a first data object second data object has been forwarded to the second data object again edited as described above. In the course of this processing, the To request to be forwarded to a third data object again and so on, until all or part of the data objects on recursive or has been run through interactively. Some accounting operations will to ensure that this process terminates.

In preferred embodiments, the link structure is the data objects with each other in such a way that any two objects are either related to each other net or are not assigned to each other. Preferably continue only assign assigned objects to a request. An assigned In some embodiments, the object can be a superordinate object (super Object) or a subordinate object (sub-object) or a related object his. The forwarding of a request can be done with regard to subordinate ob objects, but it preferably includes all parent objects and all related objects that have not yet received the request.  

Some embodiments of the invention provide the possibility that the Request a request to initialize the functionality for the deployment len is the accessibility. Such a request preferably causes a data provider for the object to which the request relates and for each of the other object to which the request is ultimately forwarded becomes. Extension objects can exist in some embodiments to process these initialization requests.

Another type of request, which is provided in preferred embodiments, is a request to obtain a collection of the names of all application data items that can be accessed via the data object to which the request refers. In other words, the names of the data elements available for access are collected by the following objects:

• - the object to which the request relates,
• - all objects that are immediate (i.e., by exactly one Mapping link follows) are assigned to this object, and
• - all objects that are transitive (i.e. by using more than one Assignment link follows) are assigned to this object.

The type of request mentioned above to collect the names of data elements that can be accessed makes a user-friendly Way to bring together information about the entire data object network to wear. The names are usually self-explanatory. Another requirement type of implementation that imple in some embodiments for user support is a requirement to get a collection of examples express. Such example expressions can also be a valuable guide deliver for the user.

Other types of requests used in most embodiments of the invention there are requirements for reading and / or setting the value an application data item.  

Preferred embodiments of the invention further comprise an evaluator (a Evaluation device), which has a user interface (front end) to the Using the data access functionality according to the invention offers. The Evalua Tor can in particular be set up to evaluate expressions that refer se on application data stored in the different data objects elements included. The result of the evaluation process can be in an application data element and may possibly be the Users are displayed. It is particularly preferred that the evaluation process is repeated when a recalculation event occurs, so that the results automatically show all changes in the data objects be fit.

In preferred embodiments of the invention, the application program used to view and / or edit documents. The application program can in particular be a CAD program. It is also preferred that the access functionality is not as the main function, but as an auxiliary Function of the application program is provided. In other words preferred embodiments of the present invention are not for use provided in connection with databases and data access programs, son They are for use in processing programs and editors for text and graphics provided.

Preferred embodiments of the computer program product and device tion of the present invention also have features that be the above written features and / or in the dependent claims correspond to defined characteristics.

Other features, objects, and advantages of the invention will appear from the following Detailed description of several embodiments of the invention. It will reference is made to the schematic drawings in which:

Fig. 1 shows a computer which executes an application program in which the present invention is implemented,

Fig. 2 shows a class diagram illustrating an example of the link structure of data objects, which are processed by the application program,

Figure 3 illustrates, an example with four data objects and their associated extension objects,

Fig. 4 is a flow chart of processing an initialization request is

Fig. 5 shows the objects of Fig. 3, after the initialization has been performed,

Fig. 6 is a flowchart of processing of a request for obtaining the name of the application data elements that can be accessed is,

Fig. 7 is a flowchart of processing a request for access to the value of an accessible data element,

Fig. 8 is a flowchart illustrating a user-controlled calculation procedure, and

FIG. 9 is a detail from the object structure of FIG. 5 after the creation of an evaluator.

The device shown in FIG. 1 is a well-known personal computer or workstation with a main unit 10 , a keyboard 12 , a mouse 14 and a video display 16 . The computer executes the CAD program based on the program sold under the "AutoCAD" brand, which has been expanded, and to implement the functionality of the present invention. The CAD program performs a wide variety of functions in connection with the display and processing of drawing and design documents in a manner known per se. Each drawing and design document contains several drawing objects, and each of the drawing objects reflects a data object processed by the CAD program.

In the example of FIG. 1, a window 18 is displayed on the video display 16 under the control of the CAD program, and two drawing objects, namely a cuboid 20 and a speech bubble 22 , are displayed in the window 18 . The speech bubble 22 contains an annotation text relating to a property of the cuboid 20 , namely the area of its front side. In previous versions of the "AutoCAD" CAD programs it was already possible to manually enter an annotation text such as that contained in the speech bubble 22 . However, in these program versions there was no direct connection between the annotation text (in particular the numerical value mentioned therein) and the actual properties of the corresponding drawing object. A possible application of the invention is that the annotation text in the speech bubble 22 can now be generated and updated automatically because an access possibility to internal data elements of the data object corresponding to the cuboid 20 is provided.

The class diagram of FIG. 2 shows an example of the interlinked class structure of the data objects processed by the CAD application program. An object of the "ASSEMBLY" class is the owner of one or more objects of the "COMPONENT DEFINITION" class (component definition = component definition = comp. Def.). This owner relationship is indicated by the small rectangle on the connecting line between the classes "ASSEMBLY" and "COMPONENT DEFINITION" in FIG. 2. Accordingly, each object of the "COMPONENT DEFINITION" class (or "COMPONENT DEFINITION" object for short) is the owner of zero or more "PARAMETER" objects. In other words, the "ASSEMBLY" object is a superordinate object in relation to each "COMPONENT DEFINITION" object, and each "PARA METER" object is an object subordinate to the corresponding "COMPONENT DEFINITION" object.

Each "COMPONENT DEFINITION" object can have a related object in the "PIECE LIST ELEMENT" class (bill of materials = BOM; element = item). The superordinate object of all "PIECE LIST ELEMENT" objects is an object of the type "PIECE LIST", which in turn is related to the "CONSTRUCTION GROUP" and the "PART LIST" object. Each of the "PIECE LIST ELEMENT" and the "COMPONENT DEFINITION" objects can have one or more "TALK BUBBLE" objects related to it (balloon = balloon). For example, the box 20 of FIG. 1 corresponds to a "COMPONENT DEFINITION" object processed by the CAD program, and the speech bubble 22 corresponds to a related "SPEECH BUBBLE" object.

Fig. 3 represents a possible object structure which can be present at any time during the execution of the CAD program. A data object 30 A has a superordinate object 30 B, a subordinate object 30 C and a related object 30 D. In the embodiment of FIG. 3 with the structure of FIG. 2, the data object 30 A can be an object of the "COMPONENT DEFINITION" class. The parent object 30 B can be a "ASSEMBLY" object, the subordinate object 30 C can be a "PARAMETER" object, and the related object 30 D can be a "SPEECH BUBBLE" object. In the language used here, two objects are "related" to one another if at least one of the objects contains a reference to the other object without being assigned as the owner or the obsessed object. Two objects are "associated" with each other if they are either related to each other in the sense defined above, or if they are an owner and an obsessed object. In other words, an "assigned object" is a superordinate object or a subordinate object or a related object.

The different names for the objects 30 A to 30 D have been chosen to meet the diverse roles of these objects in the particular example of FIG describe. 3,. It goes without saying that all four objects 30 A to 30 D are data objects which are processed by the CAD program, and that for example object 30 C can itself be a superordinate object of a further data object not shown in FIG. 3. Each of the objects 30 A to 30 D has a plurality of application data elements which represent properties of the corresponding drawing or design objects. For example, if the data object 30 A is a "COMPONENT DEFINITION" object that represents the box 20 of FIG. 1, two application data elements provided by this data object 30 A can be the height and the width of the box front.

Although the objects 30 A- 30 D shown in FIG. 3 can also be present in a CAD program according to the prior art, an important new feature of the present exemplary embodiment is that an extension object 32 A- 32 D for each of the Data objects 30 A- 30 D is provided. The expansion objects have the task of implementing various interface and accounting functions for the data access options of the present exemplary embodiment.

An important service of the extension objects 32 A- 32 D is to generate the actual data providers. The corresponding process is shown in the flow chart of FIG. 4. It is assumed that the extension object 32 A of the data object 30 A receives a request to initialize the data access functionality. This request, which only relates to the data object 30 A (and not to any other assigned object), is processed by a method of the extension object 32 A. The first step 40 of this method is to create a data provider for the data object 30 A (data provider 34 A, shown in FIG. 5). It is the primary function of the data provider to access internal data of the assigned data object. This is described in more detail below.

After the data provider 34 A ( FIG. 5) has been generated for the data object 30 A, the extension object 32 A forwards the initialization request to the corresponding extension objects 32 B- 32 D of all objects assigned to the data object 30 A. Block 42 in Fig. 4 relates to this forwarding. First, in step 44 the initialization request is sent to all superordinate objects (more precisely, to the respective extension objects of the superordinate objects). In the present example there is only one superordinate object 30 B. The corresponding extension object 32 B itself begins an execution sequence like that of FIG. 4 after receipt of the initialization request and thus generates a data provider 34 B ( FIG. 5) for the superordinate object 30 B and recursively forwards the initialization request to other assigned objects.

Similarly, the initialization in step 46, to the esterification Erwei object of the child object 32 C 30 C sent, and 32 D of the related object passes in step 48 to the extension object 30 D weiterge. Obviously, the exact order in which steps 44 through 48 are performed can be changed in execution alternatives. However, it is necessary to perform certain accounting steps to ensure that only the "right" data providers are created in this process.

The result of the initialization process is shown in Fig. 5. As he mentioned above, a data provider 34 A to 34 D has been created for each of the data objects 30 A to 30 D. The definitions of the extension objects 32 A to 32 D and the data supplier objects 34 A to 34 D together form a computer program product 50 that can be used to expand the functionality of a CAD program according to the prior art so that the new data grip options are offered.

It is understood that each implementation of a data provider is normally only suitable for one type of data object (corresponding to an object type in a drawing). In other words, the data provider 34 A- 34 D and the corresponding data object 30 A- 30 D must be tailored to one another so that the data provider 34 A- 34 D can carry out the desired data access functionality. On the other hand, because the data objects 30 A- 30 D and the data supplier objects 34 A- 34 D are independent units, the data suppliers 34 A- 34 D can be created by external developers, and the data objects 30 A to 30 D can be developed independently and to be changed. No "knowledge" of the data objects 30 A- 30 D about the data suppliers 34 A- 34 D is required.

In the present embodiment, there is no limitation on the maximum depth up to which links to assigned objects are selected be tracked after the initialization of the data providers. In execution age however, natives are considered to introduce such restrictions. While it will usually be desirable to assign all (directly and transitive nete) superordinate and all (directly and transitively assigned) relatives Covering objects of a given data object may be advisable be, connections to subordinate objects only in a limited Track dimensions. For example, a single component that the data object represents, have a plurality of holes which are incorporated in the component. While it can be useful, the data providers for each of the holes too initialize (for example, to get volume information to a provide more precise calculation possibility of the weight of the component) it may not be desirable to have any child data Collect objects of the holes so that the initialization process can be canceled when this level is reached.

The flowchart of FIG. 6, the processing of a request for a list Sustainer th the names of all data elements are, can be accessed via the object 30A. This method has a structure very similar to that of FIG. 4. In the present case, however, the request is sent to the data supplier 34 A of the data object 30 A. In step 60, the data provider 34 A outputs the names of those data elements that the data object 30 A contains. This is possible because the data provider 34 A is specially tailored to the type of data object 30 A and thus knows which data elements are made available by this data object 30 A ("are exposed").

In the steps of block 62, a search for another name is then carried out of application data elements, which must be made available from other data objects that are associated with the data object 30 A. The search begins again, in step 64 , by inquiring from the data providers of all superordinate objects (in the present example, the query is only made to the only data provider 34 B of the superordinate object 30 B). Each data provider who receives the forwarded request in turn begins executing the method of FIG. 6 and all data element names are added to the list. The process continues in step 66 with the request to data suppliers of respective subordinate objects (in the present example data supplier 34 C of the subordinate object 30 C). Finally, the request is forwarded to the data providers of all related objects (in the present example data provider 34 D of the related object 30 D).

Step 66 has been shown in FIG. 6 with dashed lines because the gathering of names of subordinate objects from the data providers is normally terminated at a certain level in order to avoid name conflicts. In continuation of the example given above, in which a single component had a plurality of holes represented by subordinate objects, each of these holes can have an application data element with the name "diameter". A distinction between these variables would trigger difficult name conflicts. Therefore, in the present embodiment, none of the "diameter" data items are added to the list. In alternative embodiments, a method is implemented to resolve such name conflicts so that more data element names can be gathered in response to the request.

Returning briefly to FIG. 2, consider the example that a request to gather the names of available application materials is directed to the data provider of the "SPEECH BUBBLE" object related to the "PIECE LIST ELEMENT" object. The "SPRECHBLASE" object itself does not provide any internal data, but it forwards the request to the data provider of the related "STÜCKLISTENELEMENT" object. This data provider provides the variable names "ELEMENT" (element = item) and "MENGE" (quantity = quantity = qty.) And forwards the request to the data providers of the higher-level object "STÜCKLISTE" and the related object "BAUTEILDEFINITION". For example, the data provider of the "PIECE LIST" object provides the mass of all elements in the parts list under the name "PIECE LIST: DIMENSIONS". The data provider of the "BAU TEILDEFINITION" object provides the mass of this component under the name "BAUTEIL: MASSE" and other attributes, for example "MATERIAL", and also forwards the request to the data providers of all subordinate objects "PARAMETER" and the parent Object "ASSEMBLY". The data provider of each "PARAMETER" object provides the parameter value with its name and adds it to the list. The data provider of the "BAU GRUPPE" object finally adds global variables, for example the name "GLOBALHÖHE" (global height = global height = globheight).

Overall, the following list of available variable names in response to the request generates: "ELEMENT, QUANTITY, PIECE LIST: DIMENSIONS, CONSTRUCTION PART: DIMENSIONS, MATERIAL, COMPONENT: LENGTH, GLOBAL HEIGHT ". Obviously this list provides a large amount of information about the type in question application data elements. Using the method of the present the embodiment it was possible to base this information on a reference to a single data object, namely the "SPEECH BUBBLE" object, to obtain. No information about the internal structure of the application data was required.

In addition to the service of obtaining the names of all accessible application data elements, the data providers 34 A- 34 D also serve for the implementation under different data access and data manipulation services. For example, the value of an application data element of the data object 30 A or of each assigned object 30 B- 30 D can be accessed.

A first exemplary embodiment of a method for processing such a request for data access is shown in FIG. 7. When the data provider 34 A of the data object 30 A receives the request, a test 70 checks whether the data object 30 A contains a data element with the name given in the request. If such a data item is available ("YES" branch from test 70 ), its value is determined in step 72 and the method sequence ends. If the data object 30 A does not contain an appropriately named data element, the request in block 74 is forwarded to all assigned objects. In the exemplary embodiment described here, this includes forwarding the request to the data providers of all superordinate objects (step 76 ), to the data providers of all subordinate objects (step 78 ) and to the data providers of all related objects (step 80 ). The data providers of the objects to which the request is forwarded in turn begin to execute the method of FIG. 7.

Obviously, this first embodiment of the data access functionality according to the method of FIG. 7 can take up an unnecessarily large amount of computing time for large networks of interconnected data objects. Therefore, several execution alternatives are considered in which the data access request is forwarded more selectively. In a second embodiment, each object that receives a forwarded data access request returns an indication of whether the request could be successfully met or not. This makes it possible to end the execution of block 74 as soon as the first successful data access is communicated by an assigned object. This optional possibility of early termination of block 74 is indicated in FIG. 7 by the dashed arrow 82 . In other alternative embodiments, the data provider of each data object manages information about the names of those data elements that are available from other assigned data objects. In this case, a data access request can be forwarded to the responsible data provider in a more direct manner than indicated in FIG. 7.

Again, it is noteworthy that the data access functionality can be used to gain access to a large number of application data elements processed by the application program, even if the internal organization of the data elements and in particular the connection structure between the data objects is not known. It is sufficient to provide a reference to a single data object 30 A with the request.

Another important functionality that is provided by the data provider object is that of setting or changing individual data elements. Processing of such a data setting request also has the structure shown in Fig. 7, with the change, of course, that step 72 is a step in which the data item is written. The same alternative embodiments as described above in connection with FIG. 7 are also possible.

Other functions that are implemented by the data providers 34 A to 34 D are, among other things, a check whether a data element with a specified name exists in the data object of a data provider or in an assigned object, the check whether a data element can be changed and checking whether new data elements can be added to the data object.

The extension objects 32 A to 32 D and the data providers 34 A to 34 D are routines on a relatively low level for access to internal application data of the CAD program. While these routines can be used by external developers and also by the end user to program extensions of the CAD program, a preferred embodiment of the computer software product (reference number 50 in FIG. 5) furthermore has an evaluator in order to implement the functionality according to the invention in a more user-friendly manner and Way to deploy. The evaluator can be used to describe text expressions, the names of data elements (enclosed in angle brackets), simple mathematical operators (e.g. "+", "-", ".", "/") And any text have to evaluate. Example expressions that can be processed by the evaluator are, for example:
"Title of the drawing: <SI: TITEL <"
"= <ST: TITEL <: The title of the current drawing"
or more generally:
"= free_text_1 <expression1 <free_text_2 <expression2 <...".

To provide improved user support, the evaluator offers also functionality, pre-set expressions for each data object strike. Such default expressions are expressions that are usually can be considered useful in connection with a particular data object. Even if the user does not immediately use any of the preset expressions At least they serve as templates to help the user formulate his or to support their own expressions, and they also contain all or at least some of the names of the available data items.

A request to obtain sample expression strings that the evaluator receives is forwarded to the extension object of a data object for which the evaluator was created. This extension object then performs a procedure similar to that shown in Figure 6, that is, it issues its own example expression string or strings and forwards the request to the extension objects of the other associated objects. In contrast to the method of FIG. 6, however, the request is processed by the extension objects 32 A- 32 D (and not by the data provider objects 34 A- 34 D) because the extension objects 32 A- 32 D are more suitable for data element names that are from a variety of different data objects come from, collect and combine them into individual example expressions.

A possible execution sequence of a method using the evaluator according to an embodiment of the invention is shown in FIG. 8. The example sequence is started by the user pointing to a data object and requesting an example expression for this object (user action 90 ). For example, and referring to FIG. 1, the user can use the mouse 14 to point to the speech bubble 22 shown on the video display 16 and request possible example expressions via a context menu.

In response to the user's pointing action, the path of the data object that is pointed to is determined in step 92 . This path, which is the complete hierarchically structured identifier of the data object, is used to generate an evaluator for the data object and to initialize it with the corresponding data provider and the extension object. FIG. 9 shows an example of such an evaluator 120 , which was generated in order to provide data access to the data object 30 A (which corresponds to the speech bubble 22 in the present example), and that with regard to the expansion object 32 A and the data provider 34 A has been initialized. The definition of the evaluator 120 is also part of the computer program product 50 of the exemplary embodiment described here.

Returning to the flowchart of Fig. 8, the evaluator 32 A now receives the list of example, expressions (step 96) from the extension object of the data object A. The 30 executed in this context, processing steps have already been generally described above. In the present example, and with reference to FIG. 1, the speech bubble 22 (for which the evaluator has been initialized) does not offer an example expression, but it forwards the request to the extension object of the associated data object, which represents the cuboid 20 . The first example expression returned in connection with the cuboid 20 can be the expression “area of the front side: <HEIGHT.WIDTH <m ^∧ 2”, which gives the area of the visible front side of the cuboid 20 . This first example expression is presented in step 98 and the user is given the opportunity to go through the other possible example expressions.

If the user confirms the selection of a sample expression in a user action 100 , the selected expression is used in the data object to which the user refers. In the present case, this expression is included in the data object that represents the speech bubble 22 . The expression is now evaluated in step 104 and the evaluation result is presented to the user as the content of the speech bubble 22 (step 106 ).

The result shown in the speech bubble 22 remains unchanged as long as the values of the data elements used in the corresponding expression do not change (waiting state 108 ). Whenever such a change has taken place or could have taken place, a recalculation event 110 is triggered automatically. In addition, recalculation of all expressions is also carried out at the user's manual request or when the entire drawing is redisplayed. Steps 104 and 106 are repeated in the course of the recalculation. This ensures that the values of expressions shown in the drawing are always correct and that they automatically reflect any modification or change in the drawing objects.

The ability of the present exemplary embodiment to evaluate expressions has been described above using the example of an expression contained in the speech bubble 22 . However, it is apparent that expressions can be used in a variety of other drawing objects as well, particularly in "PIECE LIST" and "PIECE LIST ELEMENT" objects, as well as in "PART LIST" and "NOTE" objects. As another example, the title block of a drawing could use data elements of the associated "PIECE LIST" object to represent the preset scale or to present information such as the total mass, the name of the parts list, the standard used to create the drawing. It is also readily possible to create parametric "NOTE" objects for each drawing object, and intelligent chamfer and throat annotation (which always shows the correct sizes) is possible. The data obtained from the drawing objects can also be exported to a spreadsheet, and the surface condition can indicate the attribute actually assigned to the surface if such an attribute exists.

In other alternative versions, the evaluator does not only process dimen sionsless numbers, but also units. Features are provided to to calculate the resulting units from an expression using values different basic units (e.g. millimeters and inches) and bills with different derived units (e.g. milli meter, meter, kilometer) correctly.

It is obvious that the uses and applications described above Execution alternatives are just a few examples, and that a further Scope of further applications of the teachings of the present invention both in  Connection with CAD programs as well as with regard to other applications programs exist.

Claims (19)

1. A method for providing access to application data elements of an application program, the application data elements being contained in a plurality of data objects ( 30 A- 30 D) linked to one another and processed by the application program, and the method comprising the steps:

• Receiving a request relating to at least one of the application data elements, the request relating to a data object of the plurality of data objects,
• Fulfilling the requirement with regard to the data object to which the requirement relates and
• - If the request relates to at least one other data object of the plurality of data objects, forwarding the request to the at least one other data object for further processing of the request.

2. The method of claim 1, wherein further processing the request by another data object to which the request has been forwarded comprises the steps:

• Fulfilling the request with respect to the other data object to which the request was forwarded, and
• - If the request relates to at least one further data object, forward the request to the at least one further data object for further processing of the request.

3. The method of claim 1 or claim 2, in which the data objects are linked to one another in such a way that each Data object zero or more data objects are assigned, and each of which Requirement viewed as at least some of those data objects that are assigned to the data object to which the request relates refers.   4. The method according to any one of claims 1 to 3, in which the data objects are linked to one another in such a way that each Data object associated with zero or more data objects as parent objects and assign zero or more data objects as child objects and zero or more data objects are associated as related objects, and where each request is specified as at least those data objects will see the data object to which the request relates as Super objects are assigned, and are concerned with at least those data objects fend that is related to the data object to which the request refers Objects are assigned. 5. The method according to claim 4, where each request is additionally considered as at least those data objects is aptly viewed with the data object on which the request changes as subordinate objects are linked. 6. The method of any one of claims 1 to 5, wherein the request is a request to initialize the access provisioning functionality, and wherein the step of fulfilling the request for a data object ( 30 A- 30 D) is to generate ( 40 ) one Data provider ( 34 A- 34 D) includes who is assigned to the data object ( 30 A- 30 D). 7. The method according to claim 6, wherein the request to initialize the access provision functionality is processed by at least one extension object ( 32 A- 32 D) that is assigned to the data object ( 30 A- 30 D) to which the request relates , 8. The method according to any one of claims 3 to 7, where the request is a request to get a build with is the name of all application data elements referenced via the data object that the request relates to can be accessed.   9. The method according to any one of claims 3 to 8, in which the request is a request to obtain an accumulation of Is, where the example expressions are at least some of the Contain names of the application data elements that are referenced via the data object, to which the request relates can be accessed. 10. The method of claim 8 or claim 9, which accesses via the data object to which the request relates Application data elements that can be found in the data object to which the request related application data elements contained in and in any of the application data contained in this object assigned to this object have elements. The method of any one of claims 3 to 10, wherein the request is a request to obtain ( 72 ) the value of an application data element contained in the data object to which the request relates or in any of the data objects associated with that object: 12. The method of claim 11, further comprising the steps of:

• - creating ( 94 ) an evaluator ( 120 ) for a data object;
• - calling the evaluator ( 120 ) with an expression that contains at least one name of an application data element contained in the data object or in any of the data objects assigned to this object,
• Evaluating ( 104 ) the expression using obtained values of the application data elements whose names are contained in the expression, and
• - Output ( 106 ) of the evaluation result.

13. The method of claim 12, wherein the steps of evaluating ( 104 ) printing and returning ( 106 ) the result are repeated when a recalculation event ( 110 ) occurs. 14. The method of claim 12 or claim 13, in which the result of the evaluation as an application data element is one of the data objects processed by the application program are output. 15. The method according to any one of claims 1 to 14, where the main functionality of the application program is graphical and / or textual display and / or processing of documents that the Reflect data objects. 16. The method according to any one of claims 1 to 15, where the application program is a CAD program and the application data is the drawing and / or design data created by the CAD program are processed. 17. The method according to any one of claims 1 to 16, where the accessibility as an auxiliary function of the application program provided. A computer program product ( 50 ) for execution by a computer to provide access to application data elements of an application program, the computer program product ( 50 ) having instructions which cause the computer to carry out the steps of the method according to one of claims 1 to 17. 19. A device with at least one computer programming is to carry out the steps of the method according to one of claims 1 to 17.